ISSUE BRIEF
No. 5378 | APRIL 2, 2025
DOUGLAS AND SARAH ALLISON CENTER FOR NATIONAL SECURITY
This paper, in its entirety, can be found at https://report.heritage.org/ib5378
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Extended Deterrence: A Tool
That Has Served American
Interests Since 1945
Robert Peters
America’s nuclear umbrella is a deeply
stabilizing force on global security that
enables Americans to enjoy family, faith,
and prosperity in peace.
KEY TAKEAWAYS
One of the most obvious benefits of
America’s nuclear umbrella is that it gives
the U.S. significant leverage over those
states that are underneath said umbrella.
Additionally, the top five direct investors
in the United States are all close treaty
allies currently underneath the American
nuclear umbrella.
S
ince the dawn of the nuclear age, the United
States has extended its “nuclear umbrella”
over its closest allies. This nuclear umbrella,
also referred to as an “extended deterrent,” means
that the U.S. guarantees the security of a close ally—
including through the use of nuclear weapons. Put
simply, extended deterrence means that if an adver-
sary carries out a strategic attack on an American ally
or otherwise threatens to topple said ally through con-
ventional means, the United States reserves the right
to defend that ally with all the forces at its disposal,
to include its nuclear arsenal. Generally speak-
ing, the states that are under the American nuclear
umbrella are U.S. allies in NATO, Australia, Japan, and
South Korea.
1
Today, the fear of a withdrawal of America’s
extended-deterrent guarantee to its closest allies is
